The present application relates to surface handling. It may find particular application to medical, security, and/or other applications where an object is placed on a surface and subjected to an operation using a device.
By way of example, radiographic imaging or therapy systems, such as computed tomography (CT), nuclear medicine, positron emission tomography (PET), single photon emission computed tomography (SPECT or SPET) magnetic resonance imaging (MRI), line scanners, combination(s) thereof such as PET-CT or SPECT-CT, radiotherapy systems etc., provide information, or images, of an object under examination (e.g., interior aspects of an object under examination), and/or treat aspects or regions of an object. In some systems, the object is exposed to radiation (e.g., x-rays, gamma rays,) or emits radiation (positron emissions), and one or more images are formed based upon the radiation absorbed by the object, or rather an amount of radiation that is able to pass through the object. Typically, highly dense objects absorb (e.g., attenuate) more radiation than less dense objects, and thus an object having a higher density, such as a bone or gun, for example, will be apparent when surrounded by less dense objects, such as fatty tissue or clothing, for example. A detector array, generally positioned opposite a radiation source from which radiation is emitted relative the object under examination, is configured to detect radiation that traverses the object under examination and convert such radiation into signals and/or data that may be processed to produce the image(s). Such an image(s) may be viewed by security personnel to detect threat items (e.g., weapons, etc.) and/or viewed by medical personnel to detect medical conditions (e.g., cancerous tissue).
In some scanners, such as three-dimensional imaging scanners (e.g., CT scanners, etc.), for example, the detector array and radiation source are mounted on opposing sides of a rotating gantry that forms a ring, or donut, around the object under examination. In such a scanner, the rotating gantry (including the radiation source and/or detector array) is rotated in a circle situated within an x, y plane about a z axis substantially perpendicular to the x, y plane (e.g., an “isocenter”) during an examination. The object is generally supported by a support article (e.g., a bed, conveyor belt, etc.) that runs in the z direction substantially parallel to the mechanical center of rotation (e.g., the isocenter). As the rotating gantry is rotated, radiation is substantially continuously emitted from a focal spot of the radiation source toward the object under examination.
Commonly, in one or more of the aforementioned or other systems, the examination table (e.g., where the object/patient lies during a scan or other operation) is a separate assembly that comprises its own supports attached to the floor, and the scanning or other apparatus comprises its own supports that are attached to the floor. In radiotherapy or radiation therapy, for example, where (photon) radiation is used for treatment (e.g., of cancer), a separate assembly is used for manipulating the operational surface so that that the patient is appropriately treated with a dose of radiation.
In such systems, the examination table comprises mechanical components that provide support for the patient being moved to the operational region (e.g., scan plane or dosage plane). The examination table, as a separate assembly, can be properly aligned with and coupled with a scanner or radiation dosage device so that when the patient is moved into the examination or dosage region they are in the appropriate focal plane for scanning or dosage. Currently, there are at least two reasons for having a separate examination table assembly, at least with regard to a scanning apparatus: first, providing a separate table allows the gantry to tilt the scan plane with respect to the patient; second, the separate table assembly allows independent vertical motion of the table to ease patient loading and placement in the bore of the rotating gantry.
However, these reasons for having a separate table assembly have inherent problems. The examination table must be able to cantilever the patient through the bore without appreciable motion (e.g., vibration), while also providing vertical and horizontal motions with a high degree of accuracy over a long distance. Therefore, the table needs to be properly aligned, and the (rigid) cantilevered design with accurate movements adds cost to the examination table. Moreover a separate examination table utilizes its own stable frame and skins that can also add cost, and the structure must also be firmly docked to the gantry which can prevent pre-scanning operations (e.g., patient prep.) from being performed on the target object at a location remote from the scanner.